Is there a mass update process to update a Service Request owner id in R12.0.6?

We recently implemented Oracle HRMS at which time the implementation team decided to correct erroneous employee data which resulted in a new employee record and a new resource record for a few employees using Teleservice 

I have manually corrected all "Open" Service requests where the S/R owner id contained the value from the old resource record so that they would show up in the Agent Dashboard.  Unfortunately, I have about 5,000 "Closed" Service Requests that contain the old resource owner id value.  While it may not really present a problem, I am worried about the reporting and searching for these older S/Rs, especially since the old resource record has been end-dated.